Merge pull request #2019 from scalamacros/ticket/6539

SI-6539 moves @compileTimeOnly away from scala-reflect

4 files changed, 34 insertions, 17 deletions

diff --git a/src/reflect/scala/reflect/api/Exprs.scala b/src/reflect/scala/reflect/api/Exprs.scala
index 562b1da8e3..2ba18a8207 100644
--- a/src/reflect/scala/reflect/api/Exprs.scala
+++ b/src/reflect/scala/reflect/api/Exprs.scala
@@ -90,6 +90,7 @@ trait Exprs { self: Universe =>
      * }}}
      * because expr of type Expr[T] itself does not have a method foo.
      */
+    // @compileTimeOnly("Cannot use splice outside reify")
     def splice: T
 
     /**
@@ -106,6 +107,7 @@ trait Exprs { self: Universe =>
      * object Impls { def foo_impl(c: Context)(x: c.Expr[X]): c.Expr[x.value.T] = ... }
      * }}}
      */
+    // @compileTimeOnly("Cannot use value except for signatures of macro implementations")
     val value: T
 
     override def canEqual(x: Any) = x.isInstanceOf[Expr[_]]
diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala
index 4269b65297..3806f555ac 100644
--- a/src/reflect/scala/reflect/internal/Definitions.scala
+++ b/src/reflect/scala/reflect/internal/Definitions.scala
@@ -949,7 +949,7 @@ trait Definitions extends api.StandardDefinitions {
     lazy val BeanPropertyAttr           = requiredClass[scala.beans.BeanProperty]
     lazy val BooleanBeanPropertyAttr    = requiredClass[scala.beans.BooleanBeanProperty]
     lazy val CloneableAttr              = requiredClass[scala.annotation.cloneable]
-    lazy val CompileTimeOnlyAttr        = getClassIfDefined("scala.reflect.macros.compileTimeOnly")
+    lazy val CompileTimeOnlyAttr        = getClassIfDefined("scala.reflect.internal.annotations.compileTimeOnly")
     lazy val DeprecatedAttr             = requiredClass[scala.deprecated]
     lazy val DeprecatedNameAttr         = requiredClass[scala.deprecatedName]
     lazy val DeprecatedInheritanceAttr  = requiredClass[scala.deprecatedInheritance]
diff --git a/src/reflect/scala/reflect/internal/annotations/compileTimeOnly.scala b/src/reflect/scala/reflect/internal/annotations/compileTimeOnly.scala
new file mode 100644
index 0000000000..058ff61fbf
--- /dev/null
+++ b/src/reflect/scala/reflect/internal/annotations/compileTimeOnly.scala
@@ -0,0 +1,31 @@
+package scala.reflect
+package internal
+package annotations
+
+import scala.annotation.meta._
+
+/**
+ * An annotation that designates a member should not be referred to after
+ * type checking (which includes macro expansion); it must only be used in
+ * the arguments of some other macro that will eliminate it from the AST.
+ *
+ * Later on, this annotation should be removed and implemented with domain-specific macros.
+ * If a certain method `inner` mustn't be called outside the context of a given macro `outer`,
+ * then it should itself be declared as a macro.
+ *
+ * Approach #1. Expansion of `inner` checks whether its enclosures contain `outer` and
+ * report an error if `outer` is not detected. In principle, we could use this approach right now,
+ * but currently enclosures are broken, because contexts aren't exactly famous for keeping precise
+ * track of the stack of the trees being typechecked.
+ *
+ * Approach #2. Default implementation of `inner` is just an invocation of `c.abort`.
+ * `outer` is an untyped macro, which expands into a block, which contains a redefinition of `inner`
+ * and a call to itself. The redefined `inner` could either be a stub like `Expr.splice` or  carry out
+ * domain-specific logic.
+ *
+ * @param  message the error message to print during compilation if a reference remains
+ *                 after type checking
+ * @since  2.10.1
+ */
+@getter @setter @beanGetter @beanSetter
+final class compileTimeOnly(message: String) extends scala.annotation.StaticAnnotation
diff --git a/src/reflect/scala/reflect/macros/compileTimeOnly.scala b/src/reflect/scala/reflect/macros/compileTimeOnly.scala
deleted file mode 100644
index 5a3a352a53..0000000000
--- a/src/reflect/scala/reflect/macros/compileTimeOnly.scala
+++ /dev/null
@@ -1,16 +0,0 @@
-package scala.reflect
-package macros
-
-import scala.annotation.meta._
-
-/**
- * An annotation that designates a member should not be referred to after
- * type checking (which includes macro expansion); it must only be used in
- * the arguments of some other macro that will eliminate it from the AST.
- *
- * @param  message the error message to print during compilation if a reference remains
- *                 after type checking
- * @since  2.10.1
- */
-@getter @setter @beanGetter @beanSetter
-final class compileTimeOnly(message: String) extends scala.annotation.StaticAnnotation